A fault is a fracture along which the blocks of crust on either side have moved relative to one another parallel to the fracture. It is usually detrimental to the process of engineering construction. Furthermore, an active fault has the potential to cause earthquake. In general, there are more complete geological investigation and site restriction requirements for important engineering structures, such as reservoir and nuclear power plant. However, the current law has not clear stipulation for site selection criteria of landfill. Although landfill is not like building that may cause damage to life when it is destroyed, the dirty or toxic materials leaked from landfill could pollute the environments. It is necessary to evaluate the influence of fault on the landfill site to serve the information for proper revision of current laws. In this research, an expert conference is organized. Some specialists in geology, geotechnical engineering, environmental engineering, and hydrology were invited to discuss on these topics. Both of the internal and external laws, standards, researches and cases were surveyed in this study. In addition, the performances of four landfills in Taiwan during past earthquakes are investigated. Finally, some suggestions for amendment of article are proposed in this report. This study shows that the influences of active fault are considered seriously for most managed laws of building or land. The site around the active fault is usually specified as a restricted development area, or a setback distance is stipulated. US federal law of 40 CFR part 258 required that new municipal solid waste landfill units and lateral expansions shall not be located within 60 meters of a fault that has had displacement in Holocene time. The Queensland government of Australia required 100 meters of setback distance for Holocene active fault. The similar setback requirement was also obtained from the conclusion of expert conference. The specialists suggested that the farther setback distance was needed for toxic solid waste landfill. Case studies of four landfills showed that both earthquake-induced surface ruptures and displacements by fault-slip could cause some damages to facilities of landfill. According to the results of expert conference discussion, case studies and investigations of laws and standards, this report suggests that it is properly for EPA to revise its administrant law. On the aspect of active fault, a setback distance ranging from 50 to 60 meters for sanitary landfill, 60 to 100 meters for security landfill is proposed. On the aspect of non-active fault, it needs not the setback distance, whereas the engineering measures should be adopted to overcome the potential geological problems and to prevent leakage and pollution of underground waters.

Landfill, fault, earthquake